grand action problem

[Jon Page]

Start with routine measurements:

String height for each section
Hammer center height on #'s 1 & 88

(String height) - (hammer center height) = Bore Distance

This will let you know if the hammers are too short.  Look at the string 
impressions in the crown, are they fairly centered?
Are the knuckles flattened out?  Bolstering them will get your L/O closer.

Action spread should be probably somewhere between 112.5 mm & 113.5 mm. 
Blow distance 46mm. Key Dip 10mm.

  As Ric mentioned, bed the key frame. Recheck action parameters.

Is there superfluous after touch now, because if it is minimal then 
bringing the L/O up will decrease that.
In other words, if the jack is far away from the knuckle when the key is 
fully depressed then there is
tolerance for the L/O to raise. If the jack is in very close proximity to 
the knuckle then you have to deal with
action measurements or KR.

Have you taken touchweight measurements?  If they are low (light touch) I 
would suspect KR.

Best of Luck,

Regards,

Jon Page, piano technician
Harwich Port, Cape Cod, Mass.
mailto:jonpage@comcast.net
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~